Designer baby controversy: Scientists edit genome of human embryo

By Ashley Welch

April 24, 2015 / 1:52 PM
/ CBS News

For the first time, scientists have edited DNA in human embryos, a highly controversial move garnering much criticism in the scientific community.

Using new technology, Junjiu Huang and his colleagues at the Sun Yat-sen University in Guangzhou, China, performed experiments on 86 human embryos attempting to alter the gene called HBB, which can cause a fatal blood disorder known as beta-thalassemia.

"What the Chinese did is they took human embryos that harbored a mutation that cause a certain blood disorder and they literally went in and very precisely cut out the bad piece and replaced it with a good piece to eliminate that particular disorder," Eric Schadt, director of the Icahn Institute for Genomics and Multiscale Biology at Mount Sinai Hospital in New York, explained on "CBS This Morning."

This technology could potentially be applied to other diseases based on single gene mutations, including Huntington's disease, cystic fibrosis, sickle cell anemia, and Tay-Sachs disease. While the development is exciting to many as a possible mechanism to prevent or cure these deadly diseases, it also raises serious safety questions and ethical concerns.

The chief issue is that any changes to DNA could become a permanent part of the human genetic blueprint. "As long as that lineage exists, those changes are going to be propagated to their children, their children's children, and so on," Schadt said. "We don't really understand enough of the genome to be making these types of changes." If scientists were to make a mistake, they could introduce a new disease that could be passed down to future generations.

In the report, which was published in the journal Protein & Cell, Huang tried to address such concerns, saying that his team's research used only 'non-viable' embryos, which cannot result in a live birth, obtained from local fertility clinics. But this did little to silence critics.

Another fear is that this type of experimentation could lead to so-called "designer babies," allowing parents to select traits for their children. "Beyond preventing and curing disease, it's starting to change all sorts of physical characteristics, enhancing your memory, enhancing your intelligence," Schadt said. Everything from hair and eye color to athletic ability could be on the table for potential modification.

Schadt also pointed to the ethical concern that, at least initially, this type of technology would only be available to the wealthy, creating an even bigger gap between the haves and the have nots.

He is among those urging caution before proceeding with this potentially life-changing direction of scientific research. "We're making fundamental changes to the gene pool and we don't necessarily understand how we adapt to different environmental changes," Schadt said, "and changes we may make today may not be advantageous 100 years from now."